Extracorporeal membrane oxygenation (ECMO) is lifesaving for infants with severe respiratory distress but is complicated by severe intracranial hemorrhage in 10% to 30% of patients. Intracranial venous hypertension, as a result of ligation of the internal jugular vein (IJV), has been hypothesized as a contributing factor to cerebral edema and subsequent hemorrhage. Accessory cephalad IJV cannulation may serve as a means of additional venous drainage to the pump as well as protection against intracranial venous hypertension. Proximal and distal cannulation of the IJV were studied in a primate model. The parameters monitored included sagittal sinus, right and left ventricular pressures as well as venous pressure in the ECMO circuit. The cephalad venous cannula was clamped and unclamped at 30-minute intervals. There was no significant difference in sagittal sinus or intracranial pressures during periods of cephalad cannula clamping or unclamping. Venous return was augmented when the cephalad cannula was unclamped. Cephalad cannulation has no demonstrable protective effect on intracranial, subarachnoid or venous pressures but does improve venous return to the ECMO circuit. It is concluded that cephalad venous cannulation is not necessary in all cases and should be reserved for those patients requiring additional venous drainage to support pump flow.